This invention relates to an operator-movable control lever assembly with a single lever having both friction-held and spring-centered operational modes
It is well-known to use manual control levers to remotely control hydraulic functions such as hydraulic motors or cylinders. For example, friction-held control levers are used to remotely control implement hitches on agricultural vehicles wherein the control lever is moved to a friction-held displaced position to cause the hitch to raise or lower to a new position, corresponding to the displaced control lever position. A friction-held control lever is also used to control the rotation speed of hydraulic motors where the rotation speed is maintained at a value corresponding to the control lever position. Spring-centered and detent-held control levers are used to control a hydraulic function through a selective control valve, as described in U.S. Pat. No. 3,721,160. In such an application, the control lever is moved to a detent-held displaced position to hydraulically extend or retract a hydraulic cylinder. When the hydraulic cylinder is fully raised, the detent is automatically released, for example, by a pressure increase, and the lever returns to its neutral position under the influence of a centering spring, whereupon the cylinder is held in the extended or retracted position.
Where both friction-held and spring-centered operational modes have been required, it has heretofore been necessary to provide a separate friction-held control lever and a separate spring-centered control lever for each operational mode. This has been expensive and takes up valuable space on an operator's control panel. Therefore, it would be desirable to provide a single lever control lever assembly with multiple functional modes.